Police in the city of Cherkasy said unidentified men attacked Vadym Komarov on May 4 in the center of the city, about 200 kilometers south of Kyiv. He was hospitalized and underwent unspecified surgery, and as of May 6 remained in a coma.

Officials did not say whether they believe Komarov may have been targeted for his reporting.

However, Oleksandr Radutsky, a member of the city council, said Komarov had repeatedly written about controversial issues including embezzlement of city budget funds and alleged corruption on the city council. He had also investigated the circumstances behind a prison riot at a Cherkasy penal colony.

Radutsky told the Ukrainian news site UNIAN that Komarov was shot in an apparent assassination attempt in 2016.

Sergey Tomilenko, the head of the Ukrainian Union of Journalists, said in a Facebook post on May 4 that Komarov “really annoyed many in Cherkasy, those who have great power and big money.”

He called on law enforcement agencies to thoroughly investigate the attack.

According to the U.S.-based Committee to Protect Journalists, 12 reporters have been killed in Ukraine since 1992; seven of those were specifically murdered for their work.